ACD systems distribute calls--whether inbound or outbound--for handling to any suitable ones of available call-handling agents according to some predefined criteria. In many existing systems, such as the Lucent Technologies Definity.RTM. ACD system, the criteria for handling the call from the moment that the ACD system becomes aware of the call until the call is connected to an agent are customer-specifiable (i.e., programmable by the operator of the ACD system) via a capability called call vectoring. Normally in present-day ACD systems, when the ACD system's controller detects that an agent has become available to handle a call, the controller identifies all predefined call-handling skills of the agent (usually in some order of priority) and delivers to the agent the highest-priority oldest-waiting call that matches the agent's highest-priority skill. Generally the only condition that results in a call not being delivered to an available agent is that there are no calls waiting to be handled.
In many call centers, agents are members of multiple skills (i.e., multiple agent splits corresponding to different agent skills). Some of these skills (e.g., general sales or inquiry skills) have many agent members while others (e.g., specialized sales or inquiry skills, non-native language skills, etc.) have only a few agent members. In these situations, even if the rare skill is appropriately staffed, when a rare call arrives, it is likely that all of the rare-skill agents are busy handling common-skill calls, with the result that, on average, the rare-skill call has to wait a significant amount. of time for a rare-skill agent to become available. Furthermore, the same level of service is desired across all skills. This is typically expressed as average speed of answer (ASA) or a percentage of calls answered within a specified time interval; 80 percent in 20 seconds is an industry standard.
In such call centers, however, callers to the larger, general, skills experience a higher quality or level of service than callers to the smaller, rare, skills. All other things being equal, this is due to the number of agents in the skills: the more agents there are in a skill, the higher is the level of service provided. This is due to the fact that when an incoming call arrives in a skill with no currently-available agents, the more working agents there are in the skill, the shorter is the time that the call has to wait before an agent becomes available to handle a call in that skill. In the extreme case of very rare skills, where the number of agents possessing that skill is very low, call wait-times can be so long that callers abandon the calls before the calls are answered.
A way to equalize the level of service provided to smaller skills is to overstaff these skills, either by adding agents that have only the specialized skills or by moving the agents from the larger skills. Either solution is costly and inefficient; additional training resources are also required.